Gaseous electric discharge device



Oct 6, 1936s Eye. DORGELO ET AL 9 5 GASEOUS ELECTRIC DISCHARGE DEVICEFiled March 51, 1933 g j i W ATTORNEY Patented Oct. 6, 1936 UNITEDSTATES PATENT OFFICE 2,056,648 GASEOUS ELECTRIC nrscmmca mavrcn'Application March 31, 1933, Serial No. 663,792

In the Netherlands July 27, 1932 3 Claims.

The present invention relates to gaseous electric discharge devicesgenerally and more particularly the invention relates to improvements insuch devices the gaseous atmosphere of which comprises a metalvapor.

In many cases it is desirable to maintain the container of an electricdischarge device having a gaseous atmosphere comprising a metal vapor ata high temperature in order that the metal vapor will be at acorrespondingly high pressure during the operation of the device. Themost practical method of accomplishing this result is by reducing theradiation of heat from the container to a minimum and the container ofprior devices using this method have had a double walled structure. haveproven successful in operation they are very expensive and diflicult tomanufacture and do not lend themselves readily to manufacture by anautomatic machinery.

The object of the present invention is to provide a lamp unit of simplestructure in which the container of the gaseous electric dischargedevice is at a high temperature during the operation of the lamp unit.Another object of the invention is to provide a lamp unit of the abovetype which leads itself readily to manufacture by automatic machinery. Afurther object of the invention is to provide a lamp unit the elementsof which are quickly and easily assembled. Fur- 3o ther objects andadvantages attaching to the de vice and to its use and operation will beapparent to those skilled in the art from the following particulardescription.

In accordance with these objects the new and novel lamp unit comprises agaseous electric discharge device having a gaseous atmosphere comprisinga metal vapor and a double-walled light transmitting envelope thereforseparate from said 0 container. The space between the container of thedevice and said double walled envelope is closed oii by a ring of heatinsulation material, for example. Said heat insulation ring comprises aresilient core, such as a metal spring, covered 45 with a heatinsulation material, such as asbestos. Said insulation ring fits intocircular recesses in the container of the lamp device and pressesagainst one of the walls of said double walled envelope. A lamp unithaving the above structure lends itself readily to manufacture byautomatic machinery as the gaseous electric discharge device and theenvelope therefor are made separately on standard machines well known inthe art. The container, the envelope and the heat insulating ring areeasily and quickly assembled Although such prior devicestainer 21 hastwo electron emitting cathodes 20 into a lamp unit. Further if one ofthe separate elements of the lamp unit breaks during the operation ofthe unit it is necessary to replace only that element rather than thewhole structure which makes the lamp unit a very practical de- 5 vice.

In the drawirm accompanying and forming part of this specificationseveral embodiments of the invention are illustrated in which Fig. 1 isan elevational, schematic view of one embodiment of the invention,

Fig. 2 is a top, partly sectional view of a heat insulating ring usefulin the embodiment of the invention illustrated in Fig. l and Fig. 3 isan elevational, schematicview of another embodiment of the invention.

Like numbers denote like. parts in all the figures.

Referring to Fig. l of the drawing the new and novel lamp unit comprisesa gaseous electric discharge device having an elongated container 21.Said container 21 is filled with a gaseous atmosphere, such as sodiumvapor, or a mixture comprising a rare gas, such as neon, argon, and ametal vapor, such as sodium vapor. Said conand 2| and two anodes 22 and23 sealed into the 5 stem 28 thereof. Said anodes 22 and 23 are metalcylinders connected to and surrounding said cathodes 20 and 2|. Saidcathodes 20 and 2| consist of a metal filament, such as a tungstenfilament, coated with an electron emitting material, such as bariumoxide. During the operation of the gaseous electric discharge lampdevice on alternating current the gaseous electric discharge issupported by said cathode 20 and 35 said anode 23 and by said cathode 2|and said anode 22 alternately.

A disc 29 of heat insulating material, such as a mica disc, rests onsaid stem 28 and presses against the lower part of the circularindentation 30 in the walls of said container 21. The upper part of saidcontainer 21 is filled with a gaseous mixture comprising a rare gas,such as neon, and a condensible metal vapor, such as sodium vapor. Thedisc 29 substantially or completely, as desired, seals of! the lower,stem part of said container 21 from the upper part of said container 21.The condensible metal vapor is thus prevented from entering the lowerpart of said container 21 which is the coolest part of said containerduring the operation of the gaseous electric discharge device. The undesired condensation of the condensible metal vapor in the lower part ofsaid container 21 is thus avoided during the operation of'the device. 5

- spring 3| covered with a heat insulating material 32, such asasbestos, is located in the circular indentation 39 of said container 21and presses against the inner wall of said envelope 9 to close off thespace between the inner wall of said envelope 9 and said container 21and to separate said lamp parts. Having this structure the container 21,the envelope 9 and the ring ll, 32 are quickly and easily assembled intoa lamp unit and said envelope 9 is easily removable from said container21. By virtue of this structure of the lamp unit the heat generated bythe gaseous electric discharge between the electrodes of the device isretained within the space between said container 21 and the envelope 9so that said container 21 is at a high temperature during the operationof the lamp unit to maintain the vapor in the electric discharge deviceat a correspondingly high pressure during the operation of said lampunit. The metal vapor thus participates in conducting the electricdischarge between said electrodes 22 and 23 and the spectrum of thelight emitted by the lamp unit is rich in the light rays characteristicof the metal vapor.

The embodiment of the invention illustrated in Fig. 3 is similar to thatillustrated in Fig. 1 except that in this embodiment the gaseouselectric discharge lamp device is provided with a cylindrical base 33.The outer diameter of said base 33 closely approaches the inner diameterof the inner wall of said envelope 9 to prevent the entrance of thecolder outside air into the space between the inner wall of saidenvelope 9 and said container 21. A shoulder 4| is provided on said base33 to assist in supporting said envelope 9.

Circular electrodes 35 and 36 having electrode leads 31 and 39attachedthereto respectively are sealed into the space between the innerand outer wall of said envelope 9. A gaseous atmosphere which emitslight of the same or of a difierent color as that emitted by the gas insaid container" 21 is present in said envelope 9. Where the gaseousatmosphere in said container 21 com prises sodium, for example, saidenvelope 9 is filled with neon at a pressure of approximately 1-10 mm.During the operation of the above described lamp unit the light emittedby the gaseous electric discharge between said electrodes 35 and 39complements the light emitted by the gaseous electric discharge lampdevice having the container 21. In other respects the operation of theembodiment of the invention illustrated in Fig. 3 is the same as that ofthe embodiment illustrated in Fig. 1.

While we have shown and described and have pointed out in the annexedclaims certain novel features of the invention, it will be understoodthat various omissions, substitutions and changes in the forms anddetails of the device illustrated and in its use and operation may bemade by those skilled in the art without departing from the broad spiritand scope of the invention, for example, other gaseous atmospheres suchas a mixture of argon and mercury vapor, or mercury vapor alone ispresent in the space between the inner and outer walls of said envelope9, where desired.

What we claim as new and desire to secure by Letters Patent the UnitedStates is:--

1. A lamp unit comprising in combination, a gaseous electric dischargelamp device having a container, a double walled envelope substantiallysurrounding said container, a circular recess in said container and aresilient, heat insulating ring fitted into said recess and pressingagainst the inner wall of said envelope.

2. A lamp unit comprising in combination, a gaseous electric dischargelamp device having a container, a double walled envelope substantiallysurrounding said container and a resilient, heat insulating ringinterposed between said container and the inner wall of said envelope.

3. A lamp unit comprising in combination, a gaseous electric dischargelamp device having a container, a gaseous atmosphere therein and avaporizable metal therein, said container having a stem part and aseptum closing oif said stem part from the part of said containercontaining said vaporizable metal, a double walled envelopesubstantially surrounding said container and a gasket of flexible, heatinsulating material fitting around said container and against the innersurface of said envelope, said gasket being substantially in line withsaid septum.

EDUARD G. DORGELO. CORNELIS BOL.

